#include "hcd.h"
#include "hub.h"
+#ifdef CONFIG_USB_PERSIST
+#define USB_PERSIST 1
+#else
+#define USB_PERSIST 0
+#endif
+
struct usb_hub {
struct device *intfdev; /* the "interface" device */
struct usb_device *hdev;
kick_khubd(hub);
}
-static void disconnect_all_children(struct usb_hub *hub, int logical)
-{
- struct usb_device *hdev = hub->hdev;
- int port1;
-
- for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
- if (hdev->children[port1-1]) {
- if (logical)
- hub_port_logical_disconnect(hub, port1);
- else
- usb_disconnect(&hdev->children[port1-1]);
- }
- }
-}
-
-#ifdef CONFIG_USB_PERSIST
-
-#define USB_PERSIST 1
-
-/* For "persistent-device" resets we must mark the child devices for reset
- * and turn off a possible connect-change status (so khubd won't disconnect
- * them later).
- */
-static void mark_children_for_reset_resume(struct usb_hub *hub)
-{
- struct usb_device *hdev = hub->hdev;
- int port1;
-
- for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
- struct usb_device *child = hdev->children[port1-1];
-
- if (child) {
- child->reset_resume = 1;
- clear_port_feature(hdev, port1,
- USB_PORT_FEAT_C_CONNECTION);
- }
- }
-}
-
-#else
-
-#define USB_PERSIST 0
-
-static inline void mark_children_for_reset_resume(struct usb_hub *hub)
-{ }
-
-#endif /* CONFIG_USB_PERSIST */
-
/* caller has locked the hub device */
-static void hub_pre_reset(struct usb_interface *intf)
+static int hub_pre_reset(struct usb_interface *intf)
{
struct usb_hub *hub = usb_get_intfdata(intf);
+ struct usb_device *hdev = hub->hdev;
+ int i;
- /* This routine doesn't run as part of a reset-resume, so it's safe
- * to disconnect all the drivers below the hub.
- */
- disconnect_all_children(hub, 0);
+ /* Disconnect all the children */
+ for (i = 0; i < hdev->maxchild; ++i) {
+ if (hdev->children[i])
+ usb_disconnect(&hdev->children[i]);
+ }
hub_quiesce(hub);
+ return 0;
}
/* caller has locked the hub device */
-static void hub_post_reset(struct usb_interface *intf, int reset_resume)
+static int hub_post_reset(struct usb_interface *intf)
{
struct usb_hub *hub = usb_get_intfdata(intf);
hub_power_on(hub);
- if (reset_resume) {
- if (USB_PERSIST)
- mark_children_for_reset_resume(hub);
- else {
- /* Reset-resume doesn't call pre_reset, so we have to
- * disconnect the children here. But we may not lock
- * the child devices, so we have to do a "logical"
- * disconnect.
- */
- disconnect_all_children(hub, 1);
- }
- }
hub_activate(hub);
+ return 0;
}
-
static int hub_configure(struct usb_hub *hub,
struct usb_endpoint_descriptor *endpoint)
{
spin_unlock_irqrestore(&device_state_lock, flags);
}
-
-#ifdef CONFIG_PM
-
-/**
- * usb_reset_suspended_device - reset a suspended device instead of resuming it
- * @udev: device to be reset instead of resumed
- *
- * If a host controller doesn't maintain VBUS suspend current during a
- * system sleep or is reset when the system wakes up, all the USB
- * power sessions below it will be broken. This is especially troublesome
- * for mass-storage devices containing mounted filesystems, since the
- * device will appear to have disconnected and all the memory mappings
- * to it will be lost.
- *
- * As an alternative, this routine attempts to recover power sessions for
- * devices that are still present by resetting them instead of resuming
- * them. If all goes well, the devices will appear to persist across the
- * the interruption of the power sessions.
- *
- * This facility is inherently dangerous. Although usb_reset_device()
- * makes every effort to insure that the same device is present after the
- * reset as before, it cannot provide a 100% guarantee. Furthermore it's
- * quite possible for a device to remain unaltered but its media to be
- * changed. If the user replaces a flash memory card while the system is
- * asleep, he will have only himself to blame when the filesystem on the
- * new card is corrupted and the system crashes.
- */
-int usb_reset_suspended_device(struct usb_device *udev)
-{
- int rc = 0;
-
- dev_dbg(&udev->dev, "usb %sresume\n", "reset-");
-
- /* After we're done the device won't be suspended any more.
- * In addition, the reset won't work if udev->state is SUSPENDED.
- */
- usb_set_device_state(udev, udev->actconfig
- ? USB_STATE_CONFIGURED
- : USB_STATE_ADDRESS);
-
- /* Root hubs don't need to be (and can't be) reset */
- if (udev->parent)
- rc = usb_reset_device(udev);
- return rc;
-}
-
-/**
- * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
- * @rhdev: struct usb_device for the root hub
- *
- * The USB host controller driver calls this function when its root hub
- * is resumed and Vbus power has been interrupted or the controller
- * has been reset. The routine marks @rhdev as having lost power. When
- * the hub driver is resumed it will take notice; if CONFIG_USB_PERSIST
- * is enabled then it will carry out power-session recovery, otherwise
- * it will disconnect all the child devices.
- */
-void usb_root_hub_lost_power(struct usb_device *rhdev)
-{
- dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
- rhdev->reset_resume = 1;
-}
-EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
-
-#endif /* CONFIG_PM */
-
static void choose_address(struct usb_device *udev)
{
int devnum;
#ifdef CONFIG_USB_SUSPEND
/*
+ * usb_port_suspend - suspend a usb device's upstream port
+ * @udev: device that's no longer in active use, not a root hub
+ * Context: must be able to sleep; device not locked; pm locks held
+ *
+ * Suspends a USB device that isn't in active use, conserving power.
+ * Devices may wake out of a suspend, if anything important happens,
+ * using the remote wakeup mechanism. They may also be taken out of
+ * suspend by the host, using usb_port_resume(). It's also routine
+ * to disconnect devices while they are suspended.
+ *
+ * This only affects the USB hardware for a device; its interfaces
+ * (and, for hubs, child devices) must already have been suspended.
+ *
* Selective port suspend reduces power; most suspended devices draw
* less than 500 uA. It's also used in OTG, along with remote wakeup.
* All devices below the suspended port are also suspended.
* also support "remote wakeup", where the device can activate the USB
* tree above them to deliver data, such as a keypress or packet. In
* some cases, this wakes the USB host.
+ *
+ * Suspending OTG devices may trigger HNP, if that's been enabled
+ * between a pair of dual-role devices. That will change roles, such
+ * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
+ *
+ * Devices on USB hub ports have only one "suspend" state, corresponding
+ * to ACPI D2, "may cause the device to lose some context".
+ * State transitions include:
+ *
+ * - suspend, resume ... when the VBUS power link stays live
+ * - suspend, disconnect ... VBUS lost
+ *
+ * Once VBUS drop breaks the circuit, the port it's using has to go through
+ * normal re-enumeration procedures, starting with enabling VBUS power.
+ * Other than re-initializing the hub (plug/unplug, except for root hubs),
+ * Linux (2.6) currently has NO mechanisms to initiate that: no khubd
+ * timer, no SRP, no requests through sysfs.
+ *
+ * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
+ * the root hub for their bus goes into global suspend ... so we don't
+ * (falsely) update the device power state to say it suspended.
+ *
+ * Returns 0 on success, else negative errno.
*/
-static int hub_port_suspend(struct usb_hub *hub, int port1,
- struct usb_device *udev)
+int usb_port_suspend(struct usb_device *udev)
{
- int status;
+ struct usb_hub *hub = hdev_to_hub(udev->parent);
+ int port1 = udev->portnum;
+ int status;
// dev_dbg(hub->intfdev, "suspend port %d\n", port1);
NULL, 0,
USB_CTRL_SET_TIMEOUT);
if (status)
- dev_dbg(&udev->dev,
- "won't remote wakeup, status %d\n",
- status);
+ dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
+ status);
}
/* see 7.1.7.6 */
status = set_port_feature(hub->hdev, port1, USB_PORT_FEAT_SUSPEND);
if (status) {
- dev_dbg(hub->intfdev,
- "can't suspend port %d, status %d\n",
- port1, status);
+ dev_dbg(hub->intfdev, "can't suspend port %d, status %d\n",
+ port1, status);
/* paranoia: "should not happen" */
(void) usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
return status;
}
-/*
- * usb_port_suspend - suspend a usb device's upstream port
- * @udev: device that's no longer in active use
- * Context: must be able to sleep; device not locked; pm locks held
- *
- * Suspends a USB device that isn't in active use, conserving power.
- * Devices may wake out of a suspend, if anything important happens,
- * using the remote wakeup mechanism. They may also be taken out of
- * suspend by the host, using usb_port_resume(). It's also routine
- * to disconnect devices while they are suspended.
- *
- * This only affects the USB hardware for a device; its interfaces
- * (and, for hubs, child devices) must already have been suspended.
- *
- * Suspending OTG devices may trigger HNP, if that's been enabled
- * between a pair of dual-role devices. That will change roles, such
- * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
- *
- * Devices on USB hub ports have only one "suspend" state, corresponding
- * to ACPI D2, "may cause the device to lose some context".
- * State transitions include:
- *
- * - suspend, resume ... when the VBUS power link stays live
- * - suspend, disconnect ... VBUS lost
- *
- * Once VBUS drop breaks the circuit, the port it's using has to go through
- * normal re-enumeration procedures, starting with enabling VBUS power.
- * Other than re-initializing the hub (plug/unplug, except for root hubs),
- * Linux (2.6) currently has NO mechanisms to initiate that: no khubd
- * timer, no SRP, no requests through sysfs.
- *
- * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when
- * the root hub for their bus goes into global suspend ... so we don't
- * (falsely) update the device power state to say it suspended.
- *
- * Returns 0 on success, else negative errno.
- */
-int usb_port_suspend(struct usb_device *udev)
-{
- int status = 0;
-
- status = hub_port_suspend(hdev_to_hub(udev->parent),
- udev->portnum, udev);
- return status;
-}
-
/*
* If the USB "suspend" state is in use (rather than "global suspend"),
* many devices will be individually taken out of suspend state using
- * special" resume" signaling. These routines kick in shortly after
+ * special "resume" signaling. This routine kicks in shortly after
* hardware resume signaling is finished, either because of selective
* resume (by host) or remote wakeup (by device) ... now see what changed
* in the tree that's rooted at this device.
+ *
+ * If @udev->reset_resume is set then the device is reset before the
+ * status check is done.
*/
static int finish_port_resume(struct usb_device *udev)
{
- int status;
+ int status = 0;
u16 devstatus;
/* caller owns the udev device lock */
- dev_dbg(&udev->dev, "finish resume\n");
+ dev_dbg(&udev->dev, "finish %sresume\n",
+ udev->reset_resume ? "reset-" : "");
/* usb ch9 identifies four variants of SUSPENDED, based on what
* state the device resumes to. Linux currently won't see the
? USB_STATE_CONFIGURED
: USB_STATE_ADDRESS);
+ /* 10.5.4.5 says not to reset a suspended port if the attached
+ * device is enabled for remote wakeup. Hence the reset
+ * operation is carried out here, after the port has been
+ * resumed.
+ */
+ if (udev->reset_resume)
+ status = usb_reset_device(udev);
+
/* 10.5.4.5 says be sure devices in the tree are still there.
* For now let's assume the device didn't go crazy on resume,
* and device drivers will know about any resume quirks.
*/
- status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
- if (status >= 0)
- status = (status == 2 ? 0 : -ENODEV);
+ if (status == 0) {
+ status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
+ if (status >= 0)
+ status = (status == 2 ? 0 : -ENODEV);
+ }
- if (status)
- dev_dbg(&udev->dev,
- "gone after usb resume? status %d\n",
- status);
- else if (udev->actconfig) {
+ if (status) {
+ dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
+ status);
+ } else if (udev->actconfig) {
le16_to_cpus(&devstatus);
if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP)) {
status = usb_control_msg(udev,
return status;
}
-static int
-hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
+/*
+ * usb_port_resume - re-activate a suspended usb device's upstream port
+ * @udev: device to re-activate, not a root hub
+ * Context: must be able to sleep; device not locked; pm locks held
+ *
+ * This will re-activate the suspended device, increasing power usage
+ * while letting drivers communicate again with its endpoints.
+ * USB resume explicitly guarantees that the power session between
+ * the host and the device is the same as it was when the device
+ * suspended.
+ *
+ * If CONFIG_USB_PERSIST and @udev->reset_resume are both set then this
+ * routine won't check that the port is still enabled. Furthermore,
+ * if @udev->reset_resume is set then finish_port_resume() above will
+ * reset @udev. The end result is that a broken power session can be
+ * recovered and @udev will appear to persist across a loss of VBUS power.
+ *
+ * For example, if a host controller doesn't maintain VBUS suspend current
+ * during a system sleep or is reset when the system wakes up, all the USB
+ * power sessions below it will be broken. This is especially troublesome
+ * for mass-storage devices containing mounted filesystems, since the
+ * device will appear to have disconnected and all the memory mappings
+ * to it will be lost. Using the USB_PERSIST facility, the device can be
+ * made to appear as if it had not disconnected.
+ *
+ * This facility is inherently dangerous. Although usb_reset_device()
+ * makes every effort to insure that the same device is present after the
+ * reset as before, it cannot provide a 100% guarantee. Furthermore it's
+ * quite possible for a device to remain unaltered but its media to be
+ * changed. If the user replaces a flash memory card while the system is
+ * asleep, he will have only himself to blame when the filesystem on the
+ * new card is corrupted and the system crashes.
+ *
+ * Returns 0 on success, else negative errno.
+ */
+int usb_port_resume(struct usb_device *udev)
{
- int status;
- u16 portchange, portstatus;
+ struct usb_hub *hub = hdev_to_hub(udev->parent);
+ int port1 = udev->portnum;
+ int status;
+ u16 portchange, portstatus;
+ unsigned mask_flags, want_flags;
/* Skip the initial Clear-Suspend step for a remote wakeup */
status = hub_port_status(hub, port1, &portstatus, &portchange);
status = clear_port_feature(hub->hdev,
port1, USB_PORT_FEAT_SUSPEND);
if (status) {
- dev_dbg(hub->intfdev,
- "can't resume port %d, status %d\n",
- port1, status);
+ dev_dbg(hub->intfdev, "can't resume port %d, status %d\n",
+ port1, status);
} else {
/* drive resume for at least 20 msec */
dev_dbg(&udev->dev, "usb %sresume\n",
udev->auto_pm ? "auto-" : "");
msleep(25);
-#define LIVE_FLAGS ( USB_PORT_STAT_POWER \
- | USB_PORT_STAT_ENABLE \
- | USB_PORT_STAT_CONNECTION)
-
/* Virtual root hubs can trigger on GET_PORT_STATUS to
* stop resume signaling. Then finish the resume
* sequence.
*/
status = hub_port_status(hub, port1, &portstatus, &portchange);
-SuspendCleared:
- if (status < 0
- || (portstatus & LIVE_FLAGS) != LIVE_FLAGS
- || (portstatus & USB_PORT_STAT_SUSPEND) != 0
- ) {
+
+ SuspendCleared:
+ if (USB_PERSIST && udev->reset_resume)
+ want_flags = USB_PORT_STAT_POWER
+ | USB_PORT_STAT_CONNECTION;
+ else
+ want_flags = USB_PORT_STAT_POWER
+ | USB_PORT_STAT_CONNECTION
+ | USB_PORT_STAT_ENABLE;
+ mask_flags = want_flags | USB_PORT_STAT_SUSPEND;
+
+ if (status < 0 || (portstatus & mask_flags) != want_flags) {
dev_dbg(hub->intfdev,
"port %d status %04x.%04x after resume, %d\n",
port1, portchange, portstatus, status);
USB_PORT_FEAT_C_SUSPEND);
/* TRSMRCY = 10 msec */
msleep(10);
- status = finish_port_resume(udev);
}
}
- if (status < 0)
- hub_port_logical_disconnect(hub, port1);
clear_bit(port1, hub->busy_bits);
if (!hub->hdev->parent && !hub->busy_bits[0])
usb_enable_root_hub_irq(hub->hdev->bus);
- return status;
-}
-
-/*
- * usb_port_resume - re-activate a suspended usb device's upstream port
- * @udev: device to re-activate
- * Context: must be able to sleep; device not locked; pm locks held
- *
- * This will re-activate the suspended device, increasing power usage
- * while letting drivers communicate again with its endpoints.
- * USB resume explicitly guarantees that the power session between
- * the host and the device is the same as it was when the device
- * suspended.
- *
- * Returns 0 on success, else negative errno.
- */
-int usb_port_resume(struct usb_device *udev)
-{
- int status;
-
- status = hub_port_resume(hdev_to_hub(udev->parent),
- udev->portnum, udev);
- if (status < 0)
+ if (status == 0)
+ status = finish_port_resume(udev);
+ if (status < 0) {
dev_dbg(&udev->dev, "can't resume, status %d\n", status);
+ hub_port_logical_disconnect(hub, port1);
+ }
return status;
}
return 0;
}
-static inline int
-finish_port_resume(struct usb_device *udev)
-{
- return 0;
-}
-
-static inline int
-hub_port_resume(struct usb_hub *hub, int port1, struct usb_device *udev)
-{
- return 0;
-}
-
int usb_port_resume(struct usb_device *udev)
{
- return 0;
+ int status = 0;
+
+ /* However we may need to do a reset-resume */
+ if (udev->reset_resume) {
+ dev_dbg(&udev->dev, "reset-resume\n");
+ status = usb_reset_device(udev);
+ }
+ return status;
}
static inline int remote_wakeup(struct usb_device *udev)
return 0;
}
+static int hub_reset_resume(struct usb_interface *intf)
+{
+ struct usb_hub *hub = usb_get_intfdata(intf);
+ struct usb_device *hdev = hub->hdev;
+ int port1;
+
+ hub_power_on(hub);
+
+ for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
+ struct usb_device *child = hdev->children[port1-1];
+
+ if (child) {
+
+ /* For "USB_PERSIST"-enabled children we must
+ * mark the child device for reset-resume and
+ * turn off the connect-change status to prevent
+ * khubd from disconnecting it later.
+ */
+ if (USB_PERSIST && child->persist_enabled) {
+ child->reset_resume = 1;
+ clear_port_feature(hdev, port1,
+ USB_PORT_FEAT_C_CONNECTION);
+
+ /* Otherwise we must disconnect the child,
+ * but as we may not lock the child device here
+ * we have to do a "logical" disconnect.
+ */
+ } else {
+ hub_port_logical_disconnect(hub, port1);
+ }
+ }
+ }
+
+ hub_activate(hub);
+ return 0;
+}
+
+/**
+ * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
+ * @rhdev: struct usb_device for the root hub
+ *
+ * The USB host controller driver calls this function when its root hub
+ * is resumed and Vbus power has been interrupted or the controller
+ * has been reset. The routine marks @rhdev as having lost power. When
+ * the hub driver is resumed it will take notice; if CONFIG_USB_PERSIST
+ * is enabled then it will carry out power-session recovery, otherwise
+ * it will disconnect all the child devices.
+ */
+void usb_root_hub_lost_power(struct usb_device *rhdev)
+{
+ dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
+ rhdev->reset_resume = 1;
+}
+EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
+
#else /* CONFIG_PM */
static inline int remote_wakeup(struct usb_device *udev)
return 0;
}
-#define hub_suspend NULL
-#define hub_resume NULL
+#define hub_suspend NULL
+#define hub_resume NULL
+#define hub_reset_resume NULL
#endif
static int hub_thread(void *__unused)
{
+ set_freezable();
do {
hub_events();
wait_event_interruptible(khubd_wait,
.disconnect = hub_disconnect,
.suspend = hub_suspend,
.resume = hub_resume,
+ .reset_resume = hub_reset_resume,
.pre_reset = hub_pre_reset,
.post_reset = hub_post_reset,
.ioctl = hub_ioctl,
drv = to_usb_driver(cintf->dev.driver);
if (drv->pre_reset)
(drv->pre_reset)(cintf);
+ /* FIXME: Unbind if pre_reset returns an error or isn't defined */
}
}
}
cintf->dev.driver) {
drv = to_usb_driver(cintf->dev.driver);
if (drv->post_reset)
- (drv->post_reset)(cintf, 0);
+ (drv->post_reset)(cintf);
+ /* FIXME: Unbind if post_reset returns an error or isn't defined */
}
if (cintf != iface)
up(&cintf->dev.sem);
git://bbs.cooldavid.org / net-next-2.6.git / blobdiff